Optical readers tend to fall into one of three classes: wand readers, laser scan engine optical readers, and image sensor based optical readers.
Wand readers generally comprise a single light source and single photodetector housed in a pen shaped housing. A user drags the wand reader across a decodable symbol (e.g., a bar code) and a signal is generated representative of the bar space pattern of the bar code.
Laser scan engine based optical readers comprise a laser diode assembly generating a laser light beam, a moving mirror for sweeping the laser light beam across a decodable symbol and a signal is generated corresponding to the decodable symbol.
Image sensor based optical readers comprise multi-element image sensors such as CID, CCD, and CMOS image sensors and an imaging optic for focusing an image onto the image sensor. In operation of an image sensor based optical reader, an image of a decodable symbol is focused on an image sensor, and a signal is generated corresponding to the signal.
Because of numerous advances provided by image sensor based optical readers, users of laser scanner engine based optical readers have been switching in increasing numbers to image sensor based optical readers. Image sensor based optical readers are more durable and offer additional features relative to laser scan engine based bar code readers. One function which has been incorporated into image sensor based optical readers is a picture taking function. Optical readers have been developed which can both take pictures and decode decodable symbols represented in captured image data.
U.S. Pat. No. 5,392,447 describes a hand held image sensor based optical reader having a “Photo Mode” and a “Text Mode” In the “Photo Mode,” images are captured and subjected to image compression. In a “Text Mode” decodable symbols are subjected to decoding.
U.S. Pat. No. 6,298,176, issued Oct. 2, 2001, entitled “Symbol-Controlled Image Data Reading System” describes an optical reader, which determines an image data-reading region from an image reading instruction symbol within an image and then reads image data from the image data-reading region.
In spite of the advances such as those embodied in the described prior art, it would be useful to even further advance operational functionality of picture taking optical reader.